Method for producing chlorinated hydrocarbon having chlorinated tertiary carbon

ABSTRACT

The present invention relates to a simple method for efficiently producing aromatic-substituted chlorinated hydrocarbons, for example, high-purity cumyl chloride (1,4-bis(2-chloro-2-propyl)benzene, p-DCC) that can be used as an initiator for cationic polymerization. A corresponding tertiary alcohol such as 1,4-bis(2-hydroxy-2-propyl)benzene is mixed with aqueous hydrochloric acid and subjected to stirring, and then the resulting organic layer is brought into contact with a hydrogen chloride gas to produce high-quality aromatic-substituted chlorinated hydrocarbon in high yield. Furthermore, in order to purify a mixture containing a chlorinated hydrocarbon compound, the mixture being produced by reaction between an aqueous solution of a metal hypochlorite and a protonic acid, the mixture is allowed to react with an aqueous alkaline solution to form an alcohol compound. Then, a solid is isolated by solid-liquid separation and chlorinated again with the aqueous hydrochloric acid. As a result, a high-purity chlorinated hydrocarbon compound is produced in high yield.

TECHNICAL FIELD

The present invention provides a novel and simple method for efficientlyproducing chlorinated hydrocarbons from aromatic-substituted alcoholcompounds. The present invention also relates to a method for producinga chlorinated hydrocarbon by selectively chlorinating a tertiary carbonin a hydrocarbon compound with a hypochlorite compound. Such chlorinatedhydrocarbons produced according to the present invention are useful asreagents for various synthetic reactions due to their reactivechlorine-substituted groups. It is known that aromatic-substitutedchlorinated hydrocarbons, such as 1,4-bis(2-chloro-2-propyl)benzene[1,4-dicumyl chloride, p-Cl(CH₃)₂CC₆H₄C(CH₃)₂Cl], are used as cationicpolymerization initiators in producing polyisobutylene having terminalfunctional groups or block copolymers each containing a block componentcomposed of polyisobutylene, for example, styrene-isobutylene-styrenecopolymers [U.S. Pat. Nos. 4,276,394 and 5,527,870 (Maeda et al. 1994)].

BACKGROUND ART

The following processes for producing such initiators from1,4-diisopropylbenzene are known.

In one process, 1,4-diisopropenylbenzene (CH₂═(CH₃)CC₆H₄C(CH₃)═CH₂) isprepared by dehydrogenation (U.S. Pat. No. 3,429,941) and then undergoesaddition reaction with hydrogen chloride (0. Nuyken et al., Makromol.Chem., 186, 173 (1985)). In another process,1,4-bis(2-hydroxy-2-propyl)benzene (1,4-HO(CH₃)₂CC₆H₄C(CH₃)₂OH) isprepared by air oxidation (for example, Japanese Unexamined PatentApplication Publication No. 60-174737) and is then allowed to react withhydrogen chloride (V. S.-C. Chang et al., Polymer Bulletin, 4, 513(1981)).

The above-described processes require at least two-step operations. Aprocess for producing target 1,4-dicumylchloride in a single-stepoperation by allowing 1,4-diisopropylbenzene (1,4-H(CH₃)₂CC₆H₄C(CH₃)₂H)to react with a chlorine gas under sunlight irradiation is disclosed (M.S. Kharashch et al., J. Am. Chem. Soc., 61, 2142 (1939)). A reactioninduced by light irradiation has a problem with the control ofregioselectivity in chlorination.

However, each of such conventional processes uses a hydrogen chloridegas or a chlorine gas functioning as a reagent for chlorination, thusleading to gas-liquid reaction when the processes are performed.Therefore, there are problems in which yield is significantly affectedby reaction conditions, such as stirring efficiency, and a large excessof a chlorinating reagent is required based on stoichiometry.Furthermore, the reaction must be performed at ice temperature.Consequently, these processes are not industrially advantageousprocesses.

The present inventors found a process for simply producing dicumylchloride or the like in high yield by allowing an alcohol compound, suchas 1,4-bis(2-hydroxy-2-propyl)benzene, 1,4-HO(CH₃)₂CC₆H₄C(CH₃)₂OH, toreact with hydrochloric acid (Japanese Unexamined Patent ApplicationPublication Nos. 8-291090 and 10-175892).

With respect to a process for producing 1,4-dicumyl chloride bychlorination of the benzylic positions in 1,4-diisopropylbenzene, aprocess in which sodium hypochlorite is allowed to react in the presenceof a phase-transfer catalyst (BU₄N(HSO₄)) is disclosed (H. E. Fonouni etal., J. Am. Chem. Soc, 1983, 105, 7672). However, this process uses anexpensive phase-transfer catalyst and thus is not an industriallyadvantageous. A process in which chlorination is performed withhypochlorous acid without a phase-transfer catalyst is also disclosed(F. Minisci et al., Chim. Ind., 70, 52 (1988). A process for producing1,4-dicumyl chloride by chlorination of tertiary carbons in1,4-diisopropylbenzene with hypochlorous acid has the advantages ofbeing a single step and higher selectivity compared withphotochlorination. However, hypochlorous acid is a significantlyunstable substance; hence, it is difficult to constantly preparehypochlorous acid of the same concentration and store the preparedhypochlorous acid. Therefore, when a specific amount of feed is setbased on an amount of a material, the equivalent relation between themdoes not stay the same, thus resulting in difficulties in achievingstable yield, stable selectivity, and stable product quality.

A process for producing 1,4-dicumyl chloride with hypochlorous acid isalso disclosed in Japanese Unexamined Patent Application Publication No.9-143106 but does not solve the above-described problems. Thus, JapaneseUnexamined Patent Application Publication No. 9-143106 does not providea production process suitable for commercialization. Japanese UnexaminedPatent Application Publication No. 2000-63303 also discloses a processfor producing 1,4-dicumyl chloride with hypochlorous acid. Acrystallization operation is necessary for achieving higher purity andis performed using a refrigerator with the high expense of electricity.This results in an inevitable reduction in yield.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide an easier method forproducing a high-quality chlorinated hydrocarbon compound, such asdicumyl chloride, that can be used as an initiator for cationicpolymerization.

Furthermore, even when a chlorination reaction is efficiently performedwith a hypochlorous acid compound, introducing chlorine into only adesired position with high selectivity has a limitation. A subsequentpurifying operation, such as crystallization, reduces yield. Thisresults in the difficulties with achieving commercially stable yield,stable selectivity, and stable product quality.

The present inventors found that chlorination performed by allowingaromatic group-substituted alcohol to react with aqueous hydrochloricacid functioning as a chlorinating reagent provides a high-qualitychloride in high yield without subsequent crystallization or drying ofan organic layer containing the product. This finding has led to thecompletion of the present invention. In a method for producing achlorinated hydrocarbon compound with hypochlorous acid, it is anotherobject to increase purity and yield. The present inventors elucidatedthe problems in detail and conducted extensive studies on a method forsolving the problems. As a result, the present inventors found a methodfor increasing the purity of a target compound by hydrolyzing thereaction products under an alkaline condition to form an alcoholcompound, which is a selectively isolated solid. This also has led tothe completion of the present invention.

The present invention relates to method (A) for producing a chlorinatedhydrocarbon compound represented by general formula (2):C_(n)R¹ _(m)H_(k)(CR²R³Cl)_(j)  (2)(where n is an integer of 1 to 12; m and k each represent an integer of0 to 25; j is an integer of 1 to 10; R¹ represents an atom selected fromthe group consisting of chlorine, bromine, iodine, oxygen, nitrogen,sulfur, and phosphorus, and R¹ may be the same or different when m is 2or more; a j-valent group represented by C_(n)R¹ _(m)H_(k) has notertiary carbon-hydrogen bond; and R² and R³ each represent a saturatedaliphatic hydrocarbon group containing 1 to 5 carbon atoms or asaturated aliphatic hydrocarbon group containing 1 to 5 carbon atomshaving hydrogen atoms partially substituted with halogen atoms, and R²and R³ have no tertiary carbon-hydrogen bond) by allowing a compoundrepresented by general formula (1):C_(n)R¹ _(m)H_(k)(CR²R³OH)_(j)  (1)(where m, n, k, j, R¹, R², and R³ are the same as above) to react in thepresence of aqueous hydrochloric acid and separating an organic layer byoil-water separation and then bringing the resulting organic layer intocontact with a hydrogen chloride gas;

-   -   method (B) for producing a chlorinated hydrocarbon compound        represented by general formula (2) by mixing a mixture        containing the chlorinated hydrocarbon compound represented by        general formula (2) with an aqueous alkaline solution, the        mixture being produced by reaction between an aqueous solution        of a metal hypochlorite, a protonic acid, and a compound        represented by general formula (3):        C_(n)R¹ _(m)H_(k)(CHR²R³)_(j)  (3)        (where m, n, k, j, R¹, R², and R³ are the same as above), for        purification to prepare a compound represented by general        formula (1) and then allowing the resulting reaction product        (solid), which is preferably isolated by solid-liquid        separation, to react in the presence of aqueous hydrochloric        acid; and method (C) for producing a chlorinated hydrocarbon        compound represented by general formula (2) by allowing the        reaction product (solid) prepared in method (B) to react in the        presence of aqueous hydrochloric acid and separating an organic        layer by oil-water separation and then bringing the resulting        organic layer into contact with a hydrogen chloride gas.

According to a preferred embodiment, the production method ischaracterized in that the compound represented by general formula (1) isan aromatic hydrocarbon containing a 2-hydroxy-2-propyl substituent.

According to another preferred embodiment, the production method ischaracterized in that the metal hypochlorite is selected from the groupconsisting of potassium hypochlorite, sodium hypochlorite, calciumhypochlorite, barium hypochlorite, copper hypochlorite, and copper(II)hypochlorite.

According to another preferred embodiment, the production method ischaracterized in that the protonic acid is selected from the groupconsisting of hydrochloric acid, sulfuric acid, and acetic acid.

According to another preferred embodiment, the production method ischaracterized in that the aqueous alkaline solution is an aqueoussolution of sodium hydroxide or an aqueous solution of potassiumhydroxide.

According to another preferred embodiment, the production method ischaracterized in that a halogenated organic solvent is used when thecompound represented by general formula (2) is produced from thecompound represented by general formula (3).

According to another preferred embodiment, the production method ischaracterized in that the halogenated organic solvent is used when thecompound represented by general formula (2) is produced from thecompound represented by general formula (3), the halogenated organicsolvent being selected from the group consisting of monochlorobenzene,dichlorobenzene, trichlorobenzene, ethyl chloride, ethylene dichloride,carbon tetrachloride, chloroform, methylene chloride,1-trichloro-2-trifluoroethane, and trifluoromethylbenzene.

According to another preferred embodiment, the production method ischaracterized in that an aromatic hydrocarbon solvent or an aliphatichydrocarbon solvent is used in the step of mixing the aqueous alkalinesolution to produce the compound represented by general formula (1) andthen performing solid-liquid separation, and each of the solvents isalso used for washing the resulting solid.

According to another preferred embodiment, the production method ischaracterized in that the aromatic hydrocarbon solvent or the aliphatichydrocarbon solvent is used in the step of mixing the aqueous alkalinesolution to produce the compound represented by general formula (1) andthen performing solid-liquid separation, the solvents each beingselected from the group consisting of pentane, cyclopentane, hexane,cyclohexane, heptane, benzene, toluene, and xylene.

According to another preferred embodiment, the production method ischaracterized in that a saturated hydrocarbon solvent, an aromatichydrocarbon solvent, or a halogenated organic solvent is used when thecompound represented by general formula (2) is produced from thecompound represented by general formula (1).

According to another preferred embodiment, the production method ischaracterized in that the saturated hydrocarbon solvent, the aromatichydrocarbon solvent, or the halogenated organic solvent used to producethe compound represented by general formula (2) from the compoundrepresented by general formula (1) is selected from the group consistingof pentane, cyclopentane, neopentane, hexane, cyclohexane, heptane,methylcyclohexane, octane, norbornene, ethylcyclohexane, benzene,toluene, xylene, ethylbenzene, butyl chloride, and ethyl chloride.

Examples of the aromatic-substituted alcohol represented by generalformula (1) include (2-hydroxy-2-propyl)benzene C₆H₅C(CH₃)₂OH,1,4-bis(2-hydroxy-2-propyl)benzene 1,4-HO(CH₃)₂CC₆H₄C(CH₃)₂OH,1,3-bis(2-hydroxy-2-propyl)benzene 1,3-HO(CH₃)₂CC₆H₄C(CH₃)₂OH,1,3,5-tris(2-hydroxy-2-propyl)benzene 1,3,5-((C(CH₃)₂OH)₃C₆H₃, and1,3-bis(2-hydroxy-2-propyl)-5-(tert-butyl)benzene1,3-((HOC(CH₃)₂)2-5-(C(CH₃)₃)C₆H₃.

A hydrocarbon compound represented by general formula (3)C_(n)R¹ _(m)H_(k)(CHR²R³)_(j)  (3)(where n is an integer of 1 to 12; m and k each represent an integer of0 to 25; j is an integer of 1 to 10; R¹ represents an atom selected fromthe group consisting of chlorine, bromine, iodine, oxygen, nitrogen,sulfur, and phosphorus, and R¹ may be the same or different when m is 2or more; a j-valent group represented by C_(n)R¹ _(m)H_(k) has notertiary carbon-hydrogen bond; and R² and R³ each represent a saturatedaliphatic hydrocarbon group containing 1 to 5 carbon atoms or asaturated aliphatic hydrocarbon group containing 1 to 5 carbon atomshaving hydrogen atoms partially substituted with halogen atoms, and R²and R³ have no tertiary carbon-hydrogen bond) can be used as a materialfor the present invention. R² and R³ shown in the formula preferablyeach represent a hydrocarbon group such as a methyl group, an ethylgroup, or an n-propyl group; or a hydrocarbon group containing asubstituent, such as a chlorine atom, on a carbon atom in thehydrocarbon group. In particular, R² and R³ each preferably represent amethyl group to form an isopropyl group.

Furthermore, a compound represented by general formula (4):C₆H_(6-z)(CHR⁴R⁵)_(z)  (4)(where z is an integer of 1 to 4; and R⁴ and R⁵ each represent asaturated aliphatic hydrocarbon group containing 1 to 5 carbon atoms andhas no tertiary carbon-hydrogen bond) can be suitably used. R⁴ and R⁵preferably each include a hydrocarbon group such as a methyl group, anethyl group, and n-propyl group. In particular, R⁴ and R⁵ eachpreferably represent a methyl group to form an isopropyl group.

The present invention provides a chlorinated hydrocarbon compoundrepresented by general formula (2):C_(n)R¹ _(m)H_(k)(CR²R³Cl)_(j)  (2)(where m, n, k, j, R¹, R², and R³ are the same as above) is provided bythe present invention. Preferable examples of the compound include thefollowing:

Preferable examples of a compound represented by general formula (3) ofthe present invention include the following:

In the present invention, usually, to a mixture containing an organicsolvent and an alcohol compound represented by general formula (1) isadded aqueous hydrochloric acid, followed by stirring to produce achlorinated hydrocarbon compound. The order of addition may be changedaccording to need, for example, the limitation of the production. Theresulting target compound is dissolved in an organic solvent. As aresult, the organic layer containing the target compound and an aqueouslayer of aqueous hydrochloric acid are present. Since only the organiclayer is required, the aqueous layer of hydrochloric acid is separatedfrom the organic layer. At this point in time, the target compound hasnot always satisfactory purity. In particular, the alcohol compoundundergoes dehydration, which is a side reaction in the reaction withaqueous hydrochloric acid, to form an olefin containing, for example, anisopropenyl group, thereby reducing the purity. In order to achievehigher purity, a hydrogen chloride gas is brought into contact with theorganic layer. Contact with the hydrogen chloride gas causes not onlychlorination of the unreacted alcohol that remains when reaction withaqueous hydrochloric acid is insufficient, but also addition reactionbetween the hydrogen chloride gas and the olefin containing anisopropenyl group or the like, which is a by-product, to form a targetcompound, thus resulting in higher purity. The hydrogen chloride gas maybe brought into contact with the organic layer by, but not particularlylimited to, a common technique employed for gas-liquid reaction, such asa technique for bubbling a hydrogen chloride gas or a technique formixing in a stirring vessel pressurized by a hydrogen chloride gas.

Examples of the organic solvent used in the present reaction include,but are not particularly limited insofar as a known solvent is used,saturated hydrocarbons such as pentane, cyclopentane, neopentane,hexane, cyclohexane, heptane, methylcyclohexane, octane, norbornene, andethylcyclohexane; aromatic hydrocarbons such as benzene, toluene,xylene, and ethylbenzene; halogenated hydrocarbons such as carbontetrachloride, chloroform, methylene chloride, chloroethane,dichloroethane, propyl chloride, butyl chloride, and ethyl chloride;ketones such as acetone, methyl ethyl ketone, and diethyl ketone; etherssuch as diethyl ether, diisopropyl ether, dibutyl ether, anddimethoxyethane; alcohols such as methanol, ethanol, isopropanol, andbutanol; and dimethylformamide, dimethyl sulfoxide, and HMPA.

Among these, saturated hydrocarbons, aromatic hydrocarbons, andhalogenated organic solvents are preferable because of low solubilityfor hydrochloric acid and ease of industrial use. Pentane, cyclopentane,neopentane, hexane, cyclohexane, heptane, methylcyclohexane, octane,norbornene, ethylcyclohexane, benzene, toluene, xylene, ethylbenzene,butyl chloride, and ethyl chloride are more preferable.

In the present invention, usually, the temperature during the reactionwith aqueous hydrochloric acid and a hydrogen chloride gas is preferablyset at −10° C. to 40° C., and more preferably 0° C. to 30° C., from thestandpoints of reaction rate and stability of a target substance.

The amount of the solvent used in the reaction is preferably, but is notparticularly limited to, 1 to 100 times, and more preferably 3 to 10times, that of the alcohol in weight ratio, from the standpoint ofsubsequent handling.

The hydrogen chloride content of aqueous hydrochloric acid used in thepresent invention is not particularly limited insofar as the hydrogenchloride content is one equivalent or more based on the hydroxyl groupcontent, but is preferably two equivalents or more based on the hydroxylgroup content in order to efficiently produce the target compound.

A hydrogen chloride gas introduced into a reactor is difficult to reactcompletely as long as at least a vapor phase is present in the reactor.After introducing the gas into the reactor, the gas is dissolved and/ordispersed in the solution and then consumed by reaction. The amount ofthe hydrogen chloride gas used in the present invention is notparticularly limited insofar as the amount of the gas consumed is oneequivalent or more based on the amount of an impurity containing, forexample, an isopropenyl group. In order to efficiently achieve higherpurity, the amount of the gas consumed is more preferably twoequivalents or more based on the amount of the impurity. In order toincrease the reaction rate and/or to reduce the amount of the remainingimpurity by increasing the amount of the hydrogen chloride gas dissolvedin the solution, increasing the partial pressure of the hydrogenchloride gas in the vapor phase is effective.

After the reaction, the hydrogen chloride gas remaining in the solutioncontaining a target substance is degassed by a common degassing process,for example, a process for reducing pressure or bubbling an inert gasthrough the solution.

According to the chlorination method of the present invention withaqueous hydrochloric acid and subsequently with the hydrogen chloridegas, a higher reaction temperature can be set compared with the reactiontemperature in a reaction system using a hydrogen chloride gas alonedisclosed in the above-described literature (Polymer Bulletin, 4,513-520 (1981)) In the reaction system using the hydrogen chloride gasalone, the reaction must be performed at a temperature of approximately0° C. According to the method of the present invention, a side reactionis suppressed even at about room temperature, and a target compound canbe produced in high yield. That is, in this method, the reaction can beperformed at a temperature of 10° C. or higher. In order to increase thereaction rate, the reaction temperature can be set at 15° C. to 30° C.,furthermore, at 20° C. to 30° C. An increase in reaction temperatureeliminates the need for cooling and thus simplifies the productionfacility, thereby reducing production costs.

Examples of the metal hypochlorite used in the present inventioninclude, but are not limited to, potassium hypochlorite, sodiumhypochlorite, calcium hypochlorite, barium hypochlorite, copperhypochlorite, and copper(II) hypochlorite. Among these, sodiumhypochlorite is preferable from the standpoints of ease of industrialuse, ease of handling, and excellent yield and selectivity. Theconcentration of the aqueous solution containing the metal hypochloriteis not particularly limited but is preferably 0.7 mol/kg or higher fromthe standpoints of excellent yield and selectivity. When an aqueoussolution of sodium hypochlorite obtained has a concentration of 0.7mol/kg or higher, the solution may be diluted with water for use. Inthis case, the water means, for example, tap water, ion-exchanged water,or distilled water, and may contain a metal salt, for example, NaCl orKCl, in some cases.

The amount of the aqueous solution containing the metal hypochlorite isnot particularly limited insofar as the chlorine content is oneequivalent or more based on the theoretical amount. A largely excessamount of the aqueous solution containing the metal hypochlorite usedcauses the side reaction to proceed and thus may result in the targetcompound with low purity. Accordingly, in order to efficiently producethe target compound with high purity, the molar chlorine content ispreferably 1.0 to 10 times, and particularly preferably 1.0 to 5 times,based on the theoretical amount.

Examples of the protonic acid used in the present invention include, butare not particularly limited, hydrochloric acid, sulfuric acid, nitricacid, and acetic acid. Among these, hydrochloric acid is preferable fromthe standpoints of excellent yield and selectivity. With respect to aprocess for adding the protonic acid, a continuous addition or astepwise addition is preferable, but a single-step addition may beemployed. For the continuous addition, the addition time is preferably0.5 to 15 minutes, and particularly preferably 1 to 5 minutes. Theprotonic acid should be used in an amount such that the pH of theaqueous layer in the reaction system is preferably adjusted in the rangeof 4 to 9, more preferably 5 to 7. The concentration of the protonicacid used is not particularly limited but is preferably relativelyhigher concentration from the standpoints of, for example, quality,reaction time, and the capacity of a reaction vessel for production onan industrial scale. Concentrated hydrochloric acid containing at least35 percent by weight hydrogen chloride is particularly preferable.

In the present invention, the chlorination reaction from a compoundrepresented by general formula (3) to a compound represented by generalformula (2) may be performed without solvent but is preferably performedin a state in which materials are diluted with an organic solvent. Theorganic solvent is not particularly limited but is preferably ahalogenated organic solvent, which is not easily degraded bychlorination and thus has potential for maintaining the effect ofaddition. Preferably used are monochlorobenzene, dichlorobenzene,trichlorobenzene, ethyl chloride, ethylene dichloride, carbontetrachloride, chloroform, methylene chloride,1-trichloro-2-trifluoroethane, and trifluoromethylbenzene.Monochlorobenzene, dichlorobenzene, trifluoromethylbenzene, and ethylchloride are particularly preferably used.

The temperature during the chlorination reaction is not particularlylimited, but the reaction is preferably performed at a low temperaturebecause hypochlorous acid is relatively unstable. The reaction ispreferably performed at a temperature of −15° C. to 40° C., and morepreferably −5° C. to 25° C. Reaction temperatures of higher than 40° C.accelerate the decomposition of hypochlorous acid. As a result, theconcentration of hypochlorous acid is reduced to substantially zero inthe middle of the reaction. Reaction temperatures of lower than −15° C.are not preferable due to ease of freezing. Hypochlorous acid isdecomposed to generate a hazardous chlorine gas; consequently, thereaction is preferably performed at the above-described temperaturerange from the standpoint of safety.

After the chlorination reaction, the resulting mixture containing achlorinated hydrocarbon compound represented by general formula (2)contains a large number of impurities, for example, by-products formedby the chlorination reaction. Thus, the target chlorinated hydrocarbonhas low purity. In order to efficiently remove the impurities, forexample, by-products, the mixture is mixed with an aqueous alkalinesolution to form a compound represented by general formula (1):C_(n)R¹ _(m)H_(k)(CR²R³OH)_(j)  (1)(where m, n, k, j, R¹, R², and R³ are the same as above), and then theresulting compound is isolated as a solid by solid-liquid separation,followed by purification.

The aqueous alkaline solution used in the present invention is notparticularly limited but is preferably an aqueous solution of a metalhydroxide. An aqueous solution of sodium hydroxide or an aqueoussolution of potassium hydroxide is particularly preferable due to easeof handling and ease of availability. Sodium hydroxide or potassiumhydroxide may be used in the form of a solid as it is.

The alcoholization with the aqueous alkaline solution may be performedwithout a solvent or with the remaining organic solvent used in theprevious reaction as is, but is preferably performed in a state in whichan organic solvent is further added to dilute the materials. The organicsolvent is not particularly limited but is preferably aromatichydrocarbon or aliphatic hydrocarbon, from the standpoints of highreaction selectivity; and, in the step of performing solid-liquidseparation and then purification by washing with an organic solvent, lowsolubility for an target alcohol compound represented by general formula(1) and high solubility for impurities. Among these, preferably used arepentane, cyclopentane, hexane, cyclohexane, heptane, benzene, toluene,and xylene, and particularly preferably hexane. The organic solvent ispreferably added in an amount of 10 to 200 parts by weight, andparticularly preferably 50 to 100 parts by weight, based on the amountof the organic layer containing the organic solvent used in the previousreaction.

The temperature during the alcoholization reaction with an aqueousalkaline solution is not particularly limited, but the reaction ispreferably performed at a temperature of 40° C. to 100° C., andparticularly preferably 50° C. to 80° C., from the standpoints ofreaction rate and reaction selectivity. Lower reaction temperaturesrequire a prolonged period of time for ensuring yield of a targetcompound represented by general formula (1). On the contrary, higherreaction temperatures are not preferable from the standpoint of theeffect of an aqueous alkaline solution in the reaction vessel on thematerial of the reaction vessel.

With respect to the alkali content of an aqueous alkaline solution usedin the present invention, when, for example, an aqueous solution ofsodium hydroxide or an aqueous solution of potassium hydroxide is used,the alkali content is preferably 0.1 to 10 percent by weight, morepreferably 1 to 5 percent by weight. Lower contents require a largeamount of the solution and are thus not preferable from the standpointof the capacity of the reaction vessel. Higher contents are notpreferable from the standpoints of the effect on the material of thereaction vessel and a decrease in reaction selectivity. The reactionvessel is preferably a glass-lined vessel or a Teflon-lined vessel foravoiding deterioration of quality.

Instead of feeding a large amount of the aqueous alkaline solution in asingle operation, the solution may be added in twice or more. Thisavoids adding an aqueous alkali solution with a high concentration at atime but is able to add at least an equivalent amount of an aqueousalkali solution with a low concentration required.

In solid-liquid separation for an alcohol compound represented bygeneral formula (1), a common solid-liquid separation process, such ascentrifugal separation or pressure filtration with a filter cloth, canbe performed. In order to reduce the amount of a liquid as an impurityadhering to a solid, for example, increasing a centrifugal force,prolonging filtration time, and removing the liquid by the passage of agas such as nitrogen are effective. Furthermore, performing solid-liquidseparation and then adding an organic solvent and/or pure water arerepeated. This procedure is effective in order to reduce impuritiesadhering to the solid. The organic solvent added preferably has lowsolubility for an alcohol compound represented by general formula (1).Aromatic hydrocarbons and aliphatic hydrocarbons, which are the organicsolvents used for the alcoholization described above, may be used.Toluene and hexane are particularly preferable. During the addition ofsuch an organic solvent, if possible, stirring or mixing of the solutionis also effective.

As described above, to the solid alcohol compound represented by generalformula (1) that is subjected to solid-liquid separation and thenpurified is added aqueous hydrochloric acid to yield a chlorinatedhydrocarbon compound, which is a target compound of the presentinvention, represented by general formula (2) with high purity. Thisprocess may be performed by the same process as that described above.

The resulting chlorinated hydrocarbon compound, which is represented bygeneral formula (2), produced by this reaction has high purity and thuscan be used as it is. If higher purity is required, subsequently, theresulting aqueous layer of hydrochloric acid is separated by oil-waterseparation, and then a hydrogen chloride gas is introduced into thevapor phase or the liquid phase of the organic layer containing thetarget compound, thereby being brought into contact with the organiclayer. As a result, higher purity is achieved.

Chlorinated hydrocarbon compounds, which are represented by generalformula (2), produced according to the present invention are used asreagents for various synthetic reactions due to their reactivechlorine-substituted groups. In particular, the present inventionprovides chlorinated hydrocarbon compounds with high purity. Thus, thecompounds are suitably used as initiators for the production ofpolyisobutylene with controlled terminal functional groups or variousblock copolymers each containing a block composed of polyisobutylene,for example, styrene-isobutylene-styrene copolymers.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will now be described in detail based on examples.However, the present invention is not limited to these.

EXAMPLE 1

To a conical beaker were fed 0.14 kg of toluene and 0.03 kg of1,4-bis(2-hydroxy-2-propyl)benzene (p-DIOL, manufactured by MITSUIPETROCHEMICAL Co., LTD.) and then added 0.25 kg of 35 wt % aqueoushydrochloric acid. This resulting mixture was stirred with a magneticstirrer for 90 minutes at 20° C. At this time, both of organic andaqueous layers changed to transparent and colorless. After the organiclayer was separated from the aqueous layer, a hydrogen chloride gas wasbubbled through the organic layer for 90 minutes at 20° C. understirring with the magnetic stirrer. Then, in order to remove hydrogenchloride, a nitrogen gas was bubbled for 45 minutes. A sample solutionof the resulting toluene solution of 1,4-bis(2-chloro-2-propyl)benzene(p-DCC) was devolatilized by distillation. The subsequent measurement ofa ¹H-NMR spectrum of the resulting p-DCC (crude) showed a purity of99.5%. The resulting solution of p-DCC had high quality comparable top-DCC produced by crystallization from an organic layer instead ofcontact with hydrogen chloride gas and drying, and was able to besatisfactorily used as an initiator for cationic polymerization.

EXAMPLE 2

The target compound was produced as in EXAMPLE 1 except that 35 wt %aqueous hydrochloric acid was used in an amount of 0.125 kg and thecontact reaction with the hydrogen chloride gas was performed at 5° C.As a result, p-DCC with 99.5% purity determined by NMR was produced. Theresulting solution of p-DCC had high quality comparable to p-DCCproduced by crystallization from an organic layer and drying, and wasable to be satisfactorily used as an initiator for cationicpolymerization.

EXAMPLE 3

To a glass separable flask, having a capacity of 0.002 m³, equipped witha thermometer, a baffle, and a stirrer were added 1,4-diisopropylbenzene(0.045 kg), monochlorobenzene (0.03 kg), and an aqueous solution ofsodium hypochlorite (1.2 kg, 0.9 mol/kg) under stirring and cooling inan ice bath. Subsequently, concentrated aqueous hydrochloric acid (0.08kg, 35 percent by weight) was slowly added dropwise to the solutionthrough a dropping funnel over a period of 3 minutes and stirring wascontinued for 60 minutes. After the reaction, the organic layer and theaqueous layer was separated by standing. To the separated organic layerwas added concentrated hydrochloric acid (0.03 kg, 35 percent byweight), and then the resulting mixture was vigorously stirred for about5 minutes to deactivate the hypochlorous acid finely dispersed in theorganic layer. The resulting organic layer was separated to obtain amonochlorobenzene solution of the reaction product. The yield of1,4-bis(2-chloro-2-propyl)benzene in the product was determined by gaschromatography (hereinafter, referred to as “GC”) analysis (yield:60.0%).

To the same flask that was cleaned were added the separatedmonochlorobenzene solution, 0.04 kg of hexane, and 1 kg of an aqueoussolution containing 2 wt % sodium hydroxide, and then stirring wascontinued for 5 hours at 60° C. The aqueous layer was alkaline throughthe reaction. This hydrolysis reaction provided1,4-bis(2-hydroxy-2-propyl)benzene with a selectivity of about 90%.

Subsequently, the resulting solid was washed with hexane and pure waterand then stirred in the presence of 0.3 kg of 35 wt % concentratedhydrochloric acid and 0.05 kg of toluene to yield1,4-bis(2-chloro-2-propyl)benzene. The purity determined by NMR was 95%.The ultimate yield was 45%.

EXAMPLE 4

The target compound was produced as in EXAMPLE 3 except that, inalcoholization, the reaction temperature was 50° C., and the reactiontime was 8 hours. The alcoholization provided1,4-bis(2-hydroxy-2-propyl)benzene with a selectivity of about 90%. Thesubsequent operation was performed as in EXAMPLE 3 to yield1,4-bis(2-chloro-2-propyl)benzene at the end. The purity determined byNMR was 95%. The ultimate yield was 45%.

EXAMPLE 5

The target compound was produced as in EXAMPLE 3 except that the aqueoussolution of 1 wt % sodium hydroxide was first added and the aqueoussolution of 25 wt % sodium hydroxide was added in an amount of 0.04 kgafter the confirmation that the aqueous layer showed acidic pH. Thealcoholization provided 1,4-bis(2-hydroxy-2-propyl)benzene with aselectivity of about 90%. The subsequent operation was performed as inEXAMPLE 3 to yield 1,4-bis(2-chloro-2-propyl)benzene at the end. Thepurity determined by NMR was 95%. The ultimate yield was 45%.

EXAMPLE 6

The target compound was produced as in EXAMPLE 3 except that, instead ofhexane, toluene was used as both the organic solvent added duringalcoholization and the organic solvent for washing the formed solid andthe reaction temperature was set at 75° C. The alcoholization provided1,4-bis(2-hydroxy-2-propyl)benzene with a selectivity of about 70%.

The purity, which was determined by NMR, of1,4-bis(2-chloro-2-propyl)benzene was 95%. The ultimate yield was 35%.

EXAMPLE 7

Subsequently to EXAMPLE 3, a hydrogen chloride gas was bubbled throughthe toluene solution of 1,4-bis(2-chloro-2-propyl)benzene, which was thesolution obtained at the end, under stirring with a magnetic stirrer for1.5 hours at 25° C. As a result, 1,4-bis(2-chloro-2-propyl)benzenefinally obtained had a purity of 99.5% determined by NMR. The ultimateyield was about 50%.

EXAMPLE 8

Subsequently to EXAMPLE 3, a hydrogen chloride gas was bubbled throughthe toluene solution of 1,4-bis(2-chloro-2-propyl)benzene, which was thesolution obtained at the end, for 1.5 hours at 5° C. As a result,1,4-bis(2-chloro-2-propyl)benzene finally obtained had a purity of 99.0%determined by NMR. The ultimate yield was about 50%.

COMPARATIVE EXAMPLE 1

With respect to the purity of p-DCC before the hydrogen chloride gas wasintroduced in EXAMPLE 1, a ¹H-NMR spectrum was measured after volatilecontents were distilled off. As a result, the purity was 98.0%.

COMPARATIVE EXAMPLE 2

With respect to the purity of p-DCC before the hydrogen chloride gas wasintroduced in EXAMPLE 2, a ¹H-NMR spectrum was measured after volatilecontents were distilled off. As a result, the purity was 97.0%.

COMPARATIVE EXAMPLE 3

In EXAMPLE 3, hexane was added alone instead of hexane and the aqueoussolution of 2 wt % sodium hydroxide, followed by coolingcrystallization. The purity of 1,4-bis(2-chloro-2-propyl)benzene in thedry crystals obtained was determined to be 90% by NMR. The ultimateyield was 30%.

INDUSTRIAL APPLICABILITY

According to the present invention, high-purity chlorinated hydrocarboncompounds represented by general formula: C_(n)R¹ _(m)H_(k)(CR²R³Cl)_(j)can be efficiently produced in high yield. The compounds are useful asreagents for various synthetic reactions due to their reactivechlorine-substituted groups.

1-14. (canceled)
 15. A method for producing a chlorinated hydrocarboncompound represented by general formula (2):C_(n)R¹ _(m)H_(k)(CR²R³Cl)_(j)  (2) (where n is an integer of 1 to 12; mand k each represent an integer of 0 to 25; j is an integer of 1 to 10;R¹ represents an atom selected from the group consisting of chlorine,bromine, iodine, oxygen, nitrogen, sulfur, and phosphorus, and R¹ may bethe same or different when m is 2 or more; a j-valent group representedby C_(n)R¹ _(m)H_(k) has no tertiary carbon-hydrogen bond; and R² and R³each represent a saturated aliphatic hydrocarbon group containing 1 to 5carbon atoms or a saturated aliphatic hydrocarbon group containing 1 to5 carbon atoms having hydrogen atoms partially substituted with halogenatoms, and R² and R³ have no tertiary carbon-hydrogen bond), the methodcomprising: allowing a compound represented by general formula (1):C_(n)R¹ _(m)H_(k)(CR²R³OH)_(j)  (1) (where m, n, k, j, R¹, R², and R³are the same as above) to react in the presence of aqueous hydrochloricacid; separating an organic layer by oil-water separation; and bringingthe separated organic layer into contact with a hydrogen chloride gas.16. The method for producing a chlorinated hydrocarbon compoundaccording to claim 15, wherein the compound represented by generalformula (2) is produced from the compound represented by general formula(1) in the presence of an organic solvent and aqueous hydrochloric acid.17. The method for producing a chlorinated hydrocarbon compoundaccording to claim 16, wherein the organic solvent for producing thechlorinated hydrocarbon compound represented by general formula (2) fromthe compound represented by general formula (1) is a saturatedhydrocarbon solvent, an aromatic hydrocarbon solvent, or a halogenatedorganic solvent.
 18. The method for producing a chlorinated hydrocarboncompound according to claim 16, wherein the organic solvent forproducing the chlorinated hydrocarbon compound represented by generalformula (2) from the compound represented by general formula (1) is atleast one solvent selected from the group consisting of pentane,cyclopentane, neopentane, hexane, cyclohexane, heptane,methylcyclohexane, octane, norbornene, ethylcyclohexane, benzene,toluene, xylene, ethylbenzene, butyl chloride, and ethyl chloride. 19.The method according to claim 15, wherein the compound represented bygeneral formula (1) is an aromatic hydrocarbon containing a2-hydroxy-2-propyl substituent.
 20. A method for producing a chlorinatedhydrocarbon compound represented by general formula (2), comprising:allowing a compound represented by general formula (3):C_(n)R¹ _(m)H_(k)(CHR²R³)_(j) (where m, n, k, j, R¹, R², and R³ are thesame as above) to react with an aqueous solution of a metal hypochloriteand a protonic acid to form a chlorinated hydrocarbon compoundrepresented by general formula (2), mixing the compound with an aqueousalkaline solution to form a compound represented by general formula (1),subjecting the resulting mixture to solid-liquid separation; andallowing the compound in the resulting solid to react in the presence ofaqueous hydrochloric acid to form a chlorinated hydrocarbon compoundrepresented by general formula (2)C_(n)R¹ _(m)H_(k)(CR²R³Cl)_(j)  (2)
 21. The method for producing achlorinated hydrocarbon compound according to claim 20, wherein thecompound represented by general formula (2) is produced from thecompound represented by general formula (1) in the presence of anorganic solvent and aqueous hydrochloric acid.
 22. The method accordingto claim 20, wherein the compound represented by general formula (1) isan aromatic hydrocarbon containing a 2-hydroxy-2-propyl substituent. 23.The method according to claim 20, wherein the metal hypochlorite isselected from the group consisting of potassium hypochlorite, sodiumhypochlorite, calcium hypochlorite, barium hypochlorite, copperhypochlorite, and copper(II) hypochlorite.
 24. The method according toclaim 20, wherein the protonic acid is selected from the groupconsisting of hydrochloric acid, sulfuric acid, and acetic acid.
 25. Themethod according to claim 20, wherein the aqueous alkaline solution isan aqueous solution of sodium hydroxide or potassium hydroxide.
 26. Themethod according to claim 20, wherein a halogenated organic solvent isused for producing the compound represented by general formula (2) fromthe compound represented by general formula (3).
 27. The methodaccording to claim 26, wherein the halogenated organic solvent used forproducing the compound represented by general formula (2) from thecompound represented by general formula (3) is a halogenated organicsolvent selected from the group consisting of monochlorobenzene,dichlorobenzene, trichlorobenzene, ethyl chloride, ethylene dichloride,carbon tetrachloride, chloroform, methylene chloride,1-trichloro-2-trifluoroethane, and trifluoromethylbenzene.
 28. Themethod according to claim 20, wherein an aromatic hydrocarbon oraliphatic hydrocarbon organic solvent is used in the step of mixing theaqueous alkaline solution to produce the compound represented by generalformula (1) and then performing separation by filtration, and also usedfor washing the resulting solid.
 29. The method according to claim 28,wherein the aromatic hydrocarbon or aliphatic hydrocarbon organicsolvent used in the step of mixing the aqueous alkaline solution toproduce the compound represented by general formula (1) and thenperforming separation by filtration is a solvent selected from the groupconsisting of pentane, cyclopentane, hexane, cyclohexane, heptane,benzene, toluene, and xylene.
 30. The method for producing a chlorinatedhydrocarbon compound according to claim 21, wherein the organic solventfor producing the chlorinated hydrocarbon compound represented bygeneral formula (2) from the compound represented by general formula (1)is a saturated hydrocarbon solvent, an aromatic hydrocarbon solvent, ora halogenated organic solvent.
 31. The method for producing achlorinated hydrocarbon compound according to claim 30, wherein theorganic solvent for producing the chlorinated hydrocarbon compoundrepresented by general formula (2) from the compound represented bygeneral formula (1) is at least one solvent selected from the groupconsisting of pentane, cyclopentane, neopentane, hexane, cyclohexane,heptane, methylcyclohexane, octane, norbornene, ethylcyclohexane,benzene, toluene, xylene, ethylbenzene, butyl chloride, and ethylchloride.
 32. The method according to claim 20, wherein the compoundrepresented by general formula (1) is an aromatic hydrocarbon containinga 2-hydroxy-2-propyl substituent.
 33. The method for producing achlorinated hydrocarbon compound according to claim 20, furthercomprising: separating an organic layer by oil-water separation andbringing the separated organic layer into contact with a hydrogenchloride gas.